B4i Library AS Alarm - Alarm clock or keep app active in the background

I needed a way to play a sound at a certain time even though the app is in the background. The problem is that the app is paused as soon as it goes into the background, you can delay this by 30 seconds, but if you take longer, the app is stopped and no more code is executed. Now I have found a way to work around this.

I came across the following flutter library:
When building the B4X library, I used it as a guide and learned a lot from it.

I've been using AS_Alarm in my EasyPlate app for a few months now to get a countdown in the gym between sets when my break is coming to an end. So far I haven't had any problems, the alarm has always been issued reliably, even though I was using several apps and listening to music at the same time. My next goal is to build an alarm clock app with it, but so far I haven't had the time to implement this.
I am looking forward to any feedback.

How it works
As soon as an alarm is set, a silent sound is played in the background and repeated until the alarm is set to go off, keeping the app active in the background. You can listen to your music normally during this time without any problems, the silent sound does not affect this.
The only thing that is affected is the battery life, which should also be communicated to the user if you have an alarm clock app.

Setup
1. Paste the following code to the Project Attributes in the "Main" module
Replace com.stoltex.alarm with your package name
B4X:
    #PlistExtra: <key>BGTaskSchedulerPermittedIdentifiers</key>
    #PlistExtra: <array>
    #PlistExtra:       <string>com.stoltex.alarm</string>
    #PlistExtra: </array>
    #PlistExtra: <key>UIBackgroundModes</key>
    #PlistExtra: <array>
    #PlistExtra:    <string>audio</string>
    #PlistExtra:    <string>fetch</string>
    #PlistExtra: </array>

2. Initialize the lib. in the Application_Start sub on the "Main" module
3. We need the Application_Terminate event
If the user stops the app by terminating the process, a notification is displayed that the alarm is not being executed
B4X:
'Add this to the main menu if you want to notify the user if the app is terminated and the alarm will not triggered
Private Sub Application_Terminate
    Alarm.ApplicationTerminated
End Sub
3.1. Dont miss the App.RegisterUserNotifications(True,True,True) for the notifications
3.2 You need the UserNotificationCenter class and add this to the project
3.3 You can customize the title and body of the message
B4X:
Alarm.SetNotificationOnAppKillContent("Your alarms may not ring","You killed the app. Please reopen so your alarms can be rescheduled.")

Example project is attached

Examples

B4X:
Private Sub xlbl_Start_Click
 
    'Trigger the alarm in one minute
    CreateAlarm(1,DateTime.Now + DateTime.TicksPerMinute*1,File.Combine(File.DirAssets,"alarm_1.mp3"),False)

End Sub

Private Sub CreateAlarm(Id As Int,Date As Long,AssetPath As String,LoopAudio As Boolean)
    Dim NewAlarmSettings As AS_AlarmSettings
    NewAlarmSettings.Initialize
    NewAlarmSettings.Id = Id 'Unique id for the alarm
    NewAlarmSettings.Date = Date 'When the alarm should be triggered
    NewAlarmSettings.AssetAudioPath = AssetPath 'Path to the sound file
    NewAlarmSettings.LoopAudio = LoopAudio 'Should the music be played until Alarm.StopAlarm is called up
    NewAlarmSettings.Volume = 1 '0-1 Volume
    NewAlarmSettings.FadeDuration = DateTime.TicksPerSecond*11 'Should the sound be played from quiet to loud

    Main.Alarm.SetAlarm(NewAlarmSettings)
    Log(DateUtils.TicksToString(NewAlarmSettings.Date))

End Sub

Notes:
  • The App termination notification is only displayed if an active alarm is still set
Changelog
  • 1.00
    • Release
Have Fun
 

Attachments

  • AS Alarm Example.zip
    5 KB · Views: 4
  • alarm_1.mp3.zip
    321.2 KB · Views: 4
  • AS_Alarm.b4xlib
    300.4 KB · Views: 6
Last edited:
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